Regulating systems of the Heart Flashcards
Myocardial cell
-striated in which sarcomere is functional unit
-electrical impulses spread cell to cell
-contain sign. amounts of mitochondria to supply ATP
myocytic contraction is linked to what specific ion release?
Ca+ and Na+
what is the myocardial cell triad structures:
-sarcolemma
-t tubule
-sarcoplasmic reticulum
Sarcoplasmic reticulum ?
-stores Ca+
-contain Ca+ channels and voltage receptors
T tubules allows for:
-allows for the electrical current
SA Node components :
-located in the SVC and right atrium
-UNSTABLE CELLS
- PACEMAKER POTENTIAL
AV node:
-goes through bundle of HIS, R/L branches
-interatrial septum
-near the opening of the coronary sinus
[electrical connection between atria /ventricles]
Purkinje Fibers:
formed from right and left bundles
- conduct impulses upward back toward the base
-heart is depolarized inside
SA NODE timing of impulses :
-inn: Autonomic Nerve Sys.
(-Parasympathetic division (Vagus N.)
-PACEMAKER POTENTIAL
-UNSTABLE RMP
-depolarizes every .6 sec/100 min (100 bpm)
Sympathetic division:
-cardiac plexus
Atrioventricular Node (AV) timing of impulses:
-impulse slows done
-40-60 bpm
-ANS inn: where it allows ATRIA to fully contract
(AV NODE)
Bundle of HIS/ Branches (R/L)
-impulses speeds up
-rapid depolarization of ventricle
(AV NODE)
Purkinje Fibers
-impulses from apex to myocardium ( contraction) of heart
What is the autonomic nerve supply of the heart?
Cardiac plexus
Where is the Cardiac plexus located?
near the bifurcation of the trachea
What fibers make up the plexus?
-parasympathetic
-sympathetic
what info does the afferent convey?
-reflective and nociceptive
where is the cardiac plexus located in the transverse vertebrae:
T1-T4 = cardiac plexus hehe
the sympathetic division includes the cardiac plexus in which controls:
SA/AV nodes/ myocardium
**controls body’s fight or flight response(adrenaline)
-ganglions are linked in chains
parasympathetic division:
-controls heart rate; controls body response at times of rest /digest
-Ganglions are isolated
-SA/AV nodes
The Vagus (parasympathetic nerves) does what to heart rate?
-decreases heart rate
What do sympathetic nerves do to heart rate?
-increase heart rate and force contraction
What is an electrocardiogram test used for?
-records the electrical activity of the heart
Cardiac cycle is?
duration of the time btw the beginning one heart beat to the next
What is systole?
Diastole?
-contraction ( allows for greater filling of blood) in order to effectively produce a cardiac cycle
-relaxation
what are the key events of the cardiac cycle?
-atrial contraction/depolarization (systole)
-ventricles fill up with blood=isovolumetric contraction
ventricle depolarization(systole)
relaxes ventricle
The first LUB sound of heart is what and how does it correlate to EKG?
-bicuspid and tricuspid valves
-S on EKG- ventricle depolarization (contracts) SL tricuspid Valves open
The second DUB sound of heart is what and how does it correlate to EKG?
-closure of pulmonary and aortic valves
EKG- S2 : Ventricles Replorizes (diastole) relaxed and AV open
What direction will the blood flow from:
Aortic Valve
flows upward and rightward
-2nd right intercostal
What direction will the blood flow from:
Pulmonic Valve
upward and leftward
-2nd left intercostal sp.
What direction will the blood flow from:
Tricuspid Valve
downward and leftward
-4th left intercostal sp.
What direction will the blood flow from:
Bicuspid Valve
downward and leftward to 5/6 intercostal space
midclavicular line
